Vertical hydraulic broaching machine



Nov. 1, 1938.- D. H. WEST VETRTICI.; vIIYDRAULC BROACHING MACHINE Filed Feb. l5, 1937 6 Sheets-Sheet l 4 Nov. l, 1938.

D. H. WEST VERTICAL HYDRAULIC BROACHING MACHINE Filed Feb.l l5, 1937 6 Sheets-Sheet 2 Nov. 1, 1938. 'D H. WEST 2,135,157

VERTICAL HYDRAULIC BROACHNG MACHINE I Filed Feb. 15, 1957 6 sheets-sheet s 9g l il |rf) PII Nov. 1, 1938. D. H. -wEsT VERTICAL HYDRAULIC BROACHING MACHINE Filed Feb. l5, 1937 6 Sheets-,Sheet 4 will ewa

Nov.'1, 1938.` D. H. WEST I l VERTCAL HYDRAULC BROACHING MACHINE l 6 Sheets-Sheet 5 NNN.

Filed Feb. 15, 1937 Nov. 1, 1938. D HfwEsT VERTICAL HYDRALIG VBROACHING MACHINE 6 Sheets-Sheet 6 Filed Feb. l5, 1957 a l WN v NMNNMN mm "www, Nn

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.Patented Nev. 1, 193s PATENT oFFlcE y 2,135,151 VERTICAL mimmo naoacnme MA- CHINE Donald H. West, Bolton, Mass., assignor to The Lapointe Machine Tool Company, Hudson, Mass., a corporation of Maine ,Applicati-on' February 15, 1937, Serial No. 125,871

3 Claims. This invention relates to broaching machines and particularly to hydraulically operated vertical broaching machines.

Vertical broaching machines of the pull-down type have been heretofore devised, in which the broach is drawn downward through the work by a pulling device which grips the lower end of Vthe broach. It is the general object of my invention to improve the' construction and operation of a pull-down broaching machine in such manner that it will be more reliable in operation and more satisfactory in use.

To' the attainment of this general object, I provide improved gripping members for the pulling device. together with means for automatically l releasing said gripping members. -I also provide power-actuated means for lifting the broach and returning it to its initial raised position above" the work, all under the direct control of the operator.- In the preferred form, the latter means is also operable to thereafter lower the broach for engagement with the pulling device at the beginning of a succeeding work cycle. l

"A further object of 4my invention is to provide such a combination of work-pulling and work-lifting devices that all manual manipulation-of the broach during acomplete broaching cycle is eliminated.

I also provide new and improved hydraulic mechanism by which-the various movements and operations of my improved broaching machine may be effected and controlled.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of my inventionis shown in the drawings, in which Fig. 1 is a front elevation breaching machine; Fig. 2 is a sectional side elevation of the machine:

3 is an enlarged side elevation of the lifter head;

Fig. 41s a rear elevation thereof, looking in the direction'of the arrow 4 in Fig. 3;

Fig."5 is a sectional bottom view, taken along of my improved the line 5-5 of Fig. 3;

Fig. 6 is a view similar to Fig. 3 but showing theparts in released position;

4fis an enlarged side elevation of the A 4 broach-,pulling head;

(c1. sau-33)v Fig. 9 is a partial side view similar to Fig. 'l

butshowing the parts in released position;

trating the hydraulic connections and the op.- w

eration oi my improved broaching machine.

Referring'to Figs. 1v and 2, I have shown a vvertical hydraulic broaching machine comprising a frame 20 having a bed or platen 2| on which the work is supported durin'g the broaching operation. The frame 20 also has an upwardly extending portion 22 provided with guideways 23 fora sliding block or bracket 24 from which a lifter head 25 is supported. A piston rod 26 is attached at its upper end to the vlolock or bracket 24 and is provided with a piston 21 at its lower end, 'which is slidable in a. vertical cylinder 28. j

A pipe 3|) is connected to the lower end of the cylinder 28 and a similar pipe 3| (Fig. 11) is connected to the upper end of the cylinder.

Lifter head broach B as the end of the broach ispresented 'to and entered in the lifter head 25. A plug 33 is mounted in the lifter head 25 and projects into the upper end of the recess 33 to limit inward movement of the.broach in the sleeve 34.

` A latch 40 is slidably mounted in a horizontal guideway orl bushing 4| fixed in the rear portion ,of the head 25. A projection 42 on the latch' 40 is adapted to engage a shoulder 44 forming the upper end wall of an annular recess 45, formed in the upper end portion of the broach B.

'I'he latch 40 has a cross-pin 46 located in slots 41 in the forked lower end of` a rocker a'rm 48 pivoted on a stud 49 in a rearward projection 5.0 of the head 25. A spring plunger 5is engages the upperA end of the rocker arm 48 and is forced outward by a coil spring 53. seated in an opening 54 in the rear portion of the lifter head 25. The latch 4I! is normally maintained yie1ding1y in the position shown in Fig.' 3, 1nward movement ofthelatch beinglimited .by a

ward sufciently to cause the upper end of the broach to clear the work and permit removal thereof.V As soon as the` lifter head 25 is thereafter raised above the cam' 60, the latch 40 resumes its normal position and willsnap under the shoulder 44 of the broach when the broach is again presented thereto.

Puller head The lower or puller head 64 (Fig. 2) `of my improved broaching machine is mounted in the offset lower end 85 of an elongated slide 66, movable in fixed vertical guideways 61 on the frame 20 and on its upward extension 22. At its upper end, the slide' 66 has another offset portion 68 to which is secured the upper end of a piston rod 69.

A piston 10 (Fig. 2) on the rod 69 is slidable in a xed vertical cylinder 1| having a pipe 12 connected through a passage 13 to the lower end of the cylinder and having a pipe 14 connected to the upper end of the cylinder. The elongated offset slide B6 is used for the purpose of economizing vertical space, as it permits the cylinder 1| to be mounted behind the slide 66 rather than below the pulling head 64.

The construction of the pulling head 64 is shown in detail in Figs. '7 to 10 inclusive. pulling head comprises a casing having a recess 80 open at its upper end and adapted to slidably receive the lower end of the broach B.

A pair `of broach-gripping dogs 8| are formed on studs 82 rotatably mounted in bearings in the pulling head 64, which head is formed in separable parts to permit insertion of the dogs,

and studs. The dogs 8| swing'freely in recesses within the head 64 and when the dogs are in the operative position shown in full lines in Fig. l0, the lower ends of the dogs engage an inclined annular shoulder 84 forming the lower end wall of anannular recess 85'in the lower end portion of the broach B. When the dogs 8| are moved to the dotted line position in Fig. 10, the broach is released.

An arm 81 is secured by nuts 88 on the squared outer end of one stud 82 and the arm 81 is provided with a pin 89 projecting into a slotted arm 90, clamped to the squared outer end of the second stud 82. The arms 81 and 90 cooperate to move the dogs 8| simultaneously toward or away from each other.

A tension spring 92 connects the depending lower ends of the armsj81 and 90 and normally maintains the dogs 8| yieldingly in operative or broach-gripping position.

An arm 94 is secured to a stud 82 at the opposite end from the arm 81,v and the lower end of the arm 94 is connected by a. stud 95 (Fig. '1) to a release member 96 which is slotted at 91 to receive a stud 98 on which it is slidably supported.

A cam (Fig. '1) is mounted on a rock shaft I 0| which is supported in bearings on the slide 66 and which is movable vertically with the puller head 64. A cam lever |02 projects rearward from the shaft |0| and is forked to embrace a rod |03 on which a spring |04 is mount- Theed. The upper end of the spring is seated in the under side of the fixed platen 2|.

A xed stop |06 (Fig. A'1) is positioned for engagement by the lever |02 as the puller head reaches its lower limit of travel. Such engagement moves the cam |00 from the full line to the dotted line position in Fig. 'l and moves the release member 96 to the left to the position shown in Fig. 9, thus separating the dogs 8| and releasing the broach..

As the puller head 64 thereafter moves upward and approaches its upper limit of travel, the arm |02 engages the spring |04 and the cam |00 is returned to the full-line position of Fig. '1, whereupon the dogs 8| resume operative positions.

General` operation The cooperating action of the lifter and puller heads in my improved pull-down broaching machine is briefly as follows:-

At the beginning of a work cycle, the broach B i`s held in the lifter head 25 only and occupies the raised position indicated by the line marked A in Fig. 2. The'lifter head is then lowered by the action of the piston 21 in the cylinder 28 and moves thebroach to the position indicated by the line C, at which point the lower end of the broach enters and is gripped in the puller head 64. The broach is then moved downward by the puller head to the position indicated by the line D, during which downward movement the greater part of the broaching operation is performed. During this movement the broach is engaged and guided by both the puller head 64 and the lifter head 25. y

The lifter head then releases the broach by engagement of the rocker arm 48 with the cam 60, but the puller head 64 continues its downward pulling action until the broach BV has been drawn entirely through the Work to the position indicated by the line E, at which point the dogs 8| release the broach by engagement of the lever |02 with the stop |06 (Fig. 1) as previously described.

The travel of the puller head 64 is then reversed, moving the broach upward until it again engages and is latched in the lifter head 25,

v which head is.thereafter moved upward at a Hydraulic operating and control mechanism otally mounted'rock arm or lever the lower end of which is connected through a link |I2,

cylinder 1| direction of discharge of the pump P is controlled.l For further details of the pump and its reversingA mechanism, reference is made to m'y prior patent.

The upper portion of the rock arm or lever I I I is connected through a link |I8 and bell crank IIS to a. rod |20 vertically slidable in guides or bearings I2'I mounted on the upwardly extending frame portion 22. A knock-E arm |22 is mounted on a post |23 secured to the elongated slide 66 and movable vertically therewith.

The block |22 has a vertical opening to receive the rod |20 and is freely slidable relative thereto.

ing and return strokes respectively. When so engaged, the rod and associated parts will'be moved to bring the parts to the neutralor inoperative position shown in Fig.'11, in which position the pump P will also be in neutral position and will not discharge in either direction.

A control valve mechanism V is provided between the pump P and the main cylinder 1| and the valve rod |21 thereof is connected by a link |21a to a lever |28 `pivoted atA |29 and having` its lower arm connected by a -pin and slot with the upper arm of the lever previously described. Through these connections the piston valve member will be moved axially whenever the handle IIO and lever I|| arev moved to'vary orreverse' the discharge of the pump P'.

The valve V comprises a casing having a cylindrical central opening and having a series of ports |3|,I32, |33, |34, |35, |36 and |31. The port is `cross connected by a passage |38 to the port |34. The piston valve member I4 comprises a'plurality of separate cylindrical portions spaced apart by connecting portions of reduced diameter. l

The port |3| is connected to the pipe 14 leading to the upper end of the main cylinder 1|.

The ports |32 and |33 are connected to a chamber |4I in a back pressure device |42, which device is provided with a port |43 which is connected by the pipe 12 to the lower end of the main cylinder 1|. K

An axial movable piston valve member |44 is slidable in the opening |4| and may be adjusted axially by nuts |45 threaded on the valve rod |46. The'piston valve member |44 is commonly so adjusted as to partially close the port |32 at its upper end as shown in the drawings( and for a purpose to be described.

The'port |34 is connected by'a pipe |50 to one discharge port 'I5Ii of the pump P, vand thel port |36 is connected by-a pipe |5| to the other discharge Dort |52 of the pump P. The ports |5I and |52 of the pump P mayeach function either as a discharge port aor an intake port, depending.

second-pipe |55 through a relief valve R to the tank T. A by-pass |51 is provided around the 'Ihe rod |20 is provided with collars |24 and A |25 positioned for engagement by the block |22. as the slide 66 approaches the ends of its work-A relief valve R, which by-pass hasa check valve |58, also opening away from 'the tank T.

An auxiliary pump P' is provided to supply the operating fluid for the lifter -cylinder 28, this diameter, and the piston valve is provided with a l valve rbd |62 connected to the upper end of a lever |63 pivoted at V||i4 and having its lower end connected by a link |65 to an arm |66 projecting upward from a pivoted foot lever or pedal.|61.

An additional arm |68 is secured to the lever |63 and is connected by a link |69 to a lever |10 pivoted at |1| and having connected thereto the vlower end ofa rod |12, vertically s'lidable in xed bearings |13 and |14 on the upwardly extending vportion 22 of the frame 20.

An arm |15 projects laterally from the block or bracket 24 by which theilifter head 25 is supported. The arm |15 has a vertical opening therein to loosely receive therod |12, and the rod |12\is provided with collars |16 and |11 positioned for engagement by the arm |15 at its upper and lower limits of travel respectively.

When thus engaged, the piston valve member `|6| will be moved to the neutral position shown in Figs. 12 and 13.

The casing member |60 of the control valve mechanism `V' is provided with an upper longitudinal passage and with lower longitudinal A plurality of ports |82,

passages |8| and |8|. |83 and |84 connect the upper passage |80 to the central opening |60a, and additional Aend ports |85 and |86 are provided to equalize the pressure at the .ends of the piston valve IBI.

The upper longitudinal passage |80 is connected by a pipe to the tank T and the pipe |90 is connected by a branch pipe I 9| -to the-pipe 30 which is connected to the lower end yof the cylinder 28. A check valve |92 is provided'in the pipe |9| and opens toward the-,pipe 30 and cylinder 28.

The lower passage I8| is provided with ports |95 and |96 communicating with the central opening |60, and with an external p OIft |91 connected by a pipe |98 to the discharge side of the Dump P'.

The lower passage |8IE is provided with ports 200 and 20| communicating with the central opening |60, and with an external port 202 connected by the pipe 3| to the lupper end of vthe-cylinder 28. i

The central opening |60a of the valve mechanism V is also provided withannular ports 203 and 204. The port 203 is connected by a pipe 205 through a lter 208 to an upper inletj 201 of the cooling space in the casing of the main pump P. An outlet 208 fromthe cooling space is connected by a pipe 209 tothe storage tank T. The passage of oil through the casing of the pump P is utilized to cool and lubricate the bearings and working parts of the pump P. v

vA pipe 2|0 branches off of the discharge pipe |98 of the auxiliary pump P' and is connected through a relief valve R and pipe 205 above the filter 26.

'I'he annular port 204 in the 4valve mechanism ,V is connected by a pipe 2I2 to a relief valve R2,

pipe 2I| to' the which in turn is connected by a pipe 2|3 to the` storage tank T. The discharge pipe 30 of the lifter cylinder 28 is connectedthrough a needle valve hydraulic operating and control mechanism, I

will now describe the operation of the machine with respect thereto, it being noted that in Figs.

ll to 14 the heavy arrows indicate iiow of oil under operating pressure, the light arrows indicate ow of loil to exhaust or under relatively light pressure, and the broken lines indicate' parts of the apparatus in which no flow is taking place'.

In Fig. 1l, the parts are shown at the beginning of the working stroke,` with the slide 66 and.`

puller head 64 in up position, and with the lifter head just beginning its downward stroke. In

, order to start this stroke, the foot pedal |61 has been shifted from the neutral position shown in Fig. 13 to the down stroke position shown in Fig. f l1, thereby shifting the piston`valve |6| to the right.

In this position, the valve mechanism V' connects the auxiliary pump P' through the pipe |88, passages |8| and I8| and pipe 3| to the upper end of the lifter cylinder 28, thus forcing downward the lifter head. 25 and the broach B suspended therefrom.

The lower end ofthe cylinder 28 is connected through the pipe 30, needle valve 2|l1', pipe 2|2, upper passage |80 and pipe |90 to the tank T. The rate of downward movement of the lifter head 25 is controlled by the setting of the needle valve 2|4.

The handle ||0 is in neutral or mid-position and the oil in the lower part of the main cylinder 'H cannot flow out through the pipe 12, as both parts |32 and |33 connected therewith are closed by the piston valve of the valve mechanism V. Consequently the slide 66 and puller head 64 cannot move downward so long as the handle-H0 is in neutral position.

Any surplus oil discharged by the auxiliary pump P' passes through the branch pipe 2|0, relief valve R', pipe 2| pipe 205, ller 206 and main pump casing to thepipe -209 and thus back to the tank T. The relief valve R' regulates the operating pressure in the upper end of the lifter cylinder 28.

As'soon as the lower end of the broach has passed through the work and .the supporting platen and has been brought into holding engagement with the puller head 64, the operator moves the handle ||0 to the down or operative position shown in Fig. 12. This causes the piston valve |40 to move to the right in the valve mechanism V and simultaneously adjusts the pump P to discharge through the pipe |5I, which is connected through'the valve mechanism V and pipe 14 to the upper end of the main cylinder 1|, thus moving the slide 66 and puller head 64 downward on the working stroke.

Oil from the lower end of the cylinder 1| is conducted through the pipe 12 to the cylindrical opening |4| in the back pressure device |42 and thence through the valve mechanism V to the pipes and |55. A part of the oil is returned through the pipe |50 to the pump P to replace the oil delivered therefrom to the upper` part of the cylinder 1|. and the surplus oil from the lower end of the cylinder 1| is discharged through the pipe and relief valve R to the tank T.

'I'he relief valve R counteracts gravity and prevents the main valve from moving downward too rapidly before the cutting teeth on the broach engage the work. The piston valve |44 in the back pressure device |42 throttles the exhaust from the main cylinder and prevents pulsation of the slide 66 and puller head 64, due to intermittent load Aon the broach as cutting teeth enter or leave the work.

The lifter head' 25 follows the broach B downward, with the hydraulic connections to the lifter cylinder 28 remaining as in Fig. 11, until the cam unlocksA the broach near the lower end of the working stroke, at which point the lower, collar |11 is engaged by the knock-off arm I |15, whereupon the piston valve |6| in the valve mechanism V is returned to neutral position, as shown in` Fig. 12. Y

In this position of the valve, the auxiliary pump P discharges `through the pipe |98 and ports inthe valve mechanism V to the return pipe 205, and thence through the lter 206 and theV casing of the pump P to the pipe 209 and tank T.

The piston 21 in the lifter cylinder 28 is there' after prevented from moving downward when the valve mechanism V is in' neutral, as oil from the bottom `of the cylinder cannot escape through the pipe |9| by reason of the check valve |92 and cannot escape through the needle valve 2|4 except by overcoming the relief valve R2. Consequently the lifter head 25 remains at a xed elevation during the further downward travel of the broach lB. h

Downward motion of the main piston 10, slide 66 and broach B continues until the knock-off arm |22 engages the lower collar |24 and returns the handle ||0 to neutral position, at the\ same time setting the valve mechanism V at neutral and also the main pump P.

After removing the work which has just been broached, the operator then moves the handle ||0 to the up position shown in Fig. 14, shifting the piston valve |40 to the left and starting the main piston 10 and slide 66 on their return upward st roke. At this time the lower end of the broach is seated in the puller head 64 but the dogs 8| are withdrawn, so that the broach is not locked therein.

With the handle I0 in' the up position, the pump P is set to discharge through the pipe |50, valve mechanism V and back pressure device |42 to the pipe 12 which vis connected to the lower end of the main cylinder 1|, thus forcing the piston 10upward. Oil forced out of the upper part of the cylinder 1| is discharged through the pipe 14 to the valve mechanism V where it is recirculated with the oil entering through the pipe |50 and is returned to the lower part of the cylinder 1|, thusincreasing the speed of the piston 10 on its idle or return upward stroke.

When the lifter head 25 is engaged by the upper end of the broach, the lifter head and piston 21 are pushed freely upward, during which operation oil circulates as shown in Fig. 13 from the upper end of the cylinder 28 through the pipe 3|, valve mechanism V', pipe |90, branch pipe |9| and pipe 30 to the lower end of the cylinder 28, with additional oil drawn in through the pipe from the tank T.

After the lifter head has been raised above the cam 60, so thatthe broach B is again latched in the lifter head, the foot pedal |61 is shifted to the' position shown in Fig. 111, thus moving the piston valve |6| tothe left and connecting the pump P through the pipe |98, passage |8|, port |96, annular port 204, pipe 2| 2checkY valve 2|6, by-pass 2|5 and pipe 30 to the lower end of the cylinder 28. At the same time, the upper'end of the cylinder 28 is connected through the pipe 3|, valve mechanism V' and pipe |90 tothe tank T.

Under these conditions, the lifter head is moved at greater speed than the puller head, thus drawing the broach out of the puller head before the dogs 8| are' allowed to return to -operative position at the upper end of the puller head stroke. k

When the lifter head 26 approaches its upward limit of movement, the knock-off arm |15 engages the upper collar |16 and moves the piston valve |5| in the valvev mechanism V' to neutral position, as shown in Fig. 12, in which position vment of the piston valve |40 in the valve mecha- Dump P.

The cycle of operations is thus completed and nism V and of the control mechanism of the all parts are restored to initial position.-

I have thus providedy an unusually'efiicient and reliable pull-down broaching machine of the semi-automatic hydraulic type.- Attention is particularly called to the closed construction of the puller head 64, which prevents entrance of v chips or dirtr during the broaching operation, as all operating parts are entirely enclosed within the puller head casing.

Attention is also called to the design and proportions of the dogs 8|-, which so engage the broach that an increased pull on the breachmerely locks the broach more securely in the puller head. No external clampingA device whatever is required. r 4

Having thus described my inventionfand the advantages thereof, I do not wish to be limited tothe details herein disclosed, otherwise thanas set forth in the claims, but what I claim is:-

1. In. a pull-down. breaching machine, a puller head, a pair of breach-holding dogs in said head, a rotatable cam means to render said dogs inoperative, at the end of the working down stroke of saidbroah, said cam having -an enlarged concentric portion'to hold said dogs inoperative una tilr the returnv up stroke is substantially completed, and automatic means to turn said cam alternately in opposite directions at the end of head, a reversible discharge pump for .said hydraulic mechanism, a control valve for said hy draulic mechanism, and a control device operative to move said valve and to simultaneously control the amount and direction of discharge' of said pump, whereby'both -said valve and said pump will be in neutral position at the same time.

3. In a pull-down broaching machine, a lifter y restricted ilow from-said cylinder 4during a re turn stroke of said lifter head, a. manually controlled valve for saidr lifter`cy1inder, and a relief device for said pump and cylinder providing escape of oil from said cylinder during a. working stroke of said-machine if said manually controlled valve is shifted to neutral position.

l DONALD H. WEST. 

